FileWriter stats

[mnightingale]

sabctools.write_stats() returns totals for every write through every FileWriter: count, bytes, nanoseconds spent inside the write, and the slowest single write.

The per-architecture vendored builds no longer inherit universal2 -arch flags, which made CMake reject each slice before compiling anything - build issue caused by build_macos passing CFLAGS (nothing wrong with existing wheels)

[Safihre]

I still don't fully understand why you don't want to clear stats also in sabctools?
And is there no risk of integer overflow in case somebody keeps SAB running for months?

[mnightingale]

It doesn't make a whole lot of difference on the Sab side, but I don't think we are ever going to need more than one consumer so switched it to C having a reset option. But I suppose getting each read with reset naturally only covering that window is simpler to consume.

Not relevant now but overflow is not a risk, at 10 Gbps it'd take >450 years.